One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(10,14)(11,16)(17,18,20,22)(19,21,23,24)(25,26,31,29)(27,33,28,32)(30,37,38,34)(35,39,36,40)(10,14)(11,16)(19,23)(21,24)(25,27,31,28)(26,32,29,33)(30,35,38,36)(34,39,37,40)(9,10)(11,15)(12,16)(13,14)(17,18)(19,21)(20,22)(23,24)(25,28,31,27)(26,33,29,32)(30,36,38,35)(34,40,37,39)(1,2)(3,6)(4,5)(7,8)(9,11,13,16)(10,15,14,12)(17,19,20,23)(18,21,22,24)(25,29,31,26)(27,32,28,33)(30,37,38,34)(35,39,36,40)(1,3,4,7)(2,6,5,8)(9,12,13,15)(10,16,14,11)(25,30)(26,34)(27,35)(28,36)(29,37)(31,38)(32,39)(33,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.